It has been recognized that chimney fires are one of the leading causes of fires in buildings with frame construction. A chimney fire may smoulder for an extended period of time. It may only be detected after it has involved other parts of the structure or the building.
Known buildings with frame construction which incorporate chimneys or flues usually provide an air space between the sides of the chimney or flue in the adjacent walls. The air space or gap provides a form of insulation and separates the wall from the side of the chimney or flue.
Because the interior walls usually surround those portions of the chimney or flue which are within the building, the air space or gap between the adjacent walls and the surfaces of the chimney or flue is usually not accessible for monitoring purposes. It would be desirable to be able to monitor ambient conditions in the air space. Potential monitorable conditions include the presence of smoke, gas and temperature in the air and the gap.
There is thus a need for a detector structure which is suitable for monitoring ambient conditions in the gap or space between respective wall(s) and adjacent surfaces of a chimney or flue. Preferably, such devices could be installed in new construction as well as in existing buildings. It would be preferable also if such detectors had an esthetically acceptable appearance once installed. Further, it would be desirable to be able to readily conduct maintenance and check operational conditions of the respective detector after installation.
It would also be desirable if the design of such detector overcame problems associated with use of current smoke or fire detectors which are not suitable for monitoring the gap or space between the wall of the flue since they must be installed entirely within the protected area. Since they must be regularly maintained to provide ongoing proper operation such installations are not feasible.